Rapid detection of biological warfare agents is one of the first lines of defense against bioterrorism. The development of multiplexed sensors capable of detecting any known biological warfare agent will be essential to rapidly implement measures to protect the population and military personnel from biological attack. The goal of this proposal is to develop an ultraminiaturized, sensitive biological warfare agent detection system. BioForce's NanoArray chip technology is based on affinity capture of pathogens using solid phase antibody arrays and Atomic Force Microscopy (AFM). Antibodies to bacteria or viral pathogens are deposited in an addressable array on a solid surface of a chip. Binding of bacterial spores or viral particles to antibodies in defined spatial domains on the chip are detected by direct observation, using AFM, of a topographic change at that address, and the pathogen identity thereby determined. The advantage of our technology is that it has the potential to directly detect bacterial spores, such as anthrax, without any sample preparation and determine the number of spores in a sample, rapidly, accurately and with high specificity. We have already provided proof of principle that our technology can detect viral pathogens. We propose to adapt this technology to detect biological warfare agents. In these phase I studies, we will develop a NanoArray composed of antibodies against surface antigens that can detect simulants of biological warfare agents such as B. globigii and MS2 bacteriophage. Chemistries will be developed to attach these antisera to chip surfaces using similar procedures as we have employed to attach antibodies on chip surfaces to capture viral particles. We will use AFM to detect simulant binding to antibodies on the NanoArray. The sensitivity, reaction kinetics and specificity for AFM detection will be determined for each simulant alone, in combination or in the presence of other bacteria or viruses. The assay will be optimized for quantitation of pathogens. If these studies are successful, then in future studies (Phase II SBIR), we will develop a NanoArray/AFM system to detect all known biological warfare agents which can serve as a general sensor to protect the public and military personal from bioterrorism.